Debunking the Myth: Can Dogs Digest Kibble and Raw Food at the Same Time?
Written Anna Shaw & Libby Halpin
The debate surrounding whether dogs can digest kibble and raw food simultaneously has been a persistent topic of discussion among pet owners and nutritionists. A primary concern stems from the belief that these two types of food digest at different rates and require different levels of gut acidity, potentially leading to digestive issues. However, this notion is largely a misconception. Let's delve into the science and practical observations to understand why.
Understanding Canine Digestion
Dogs possess highly acidic stomachs, often compared to battery acid, which allows them to efficiently digest a variety of foods [1]. This acidity is crucial for breaking down proteins and killing harmful bacteria. The idea that kibble and raw food digest at significantly different rates and therefore should not be mixed is not supported by scientific evidence [1, 2, 3]. Dogs have a relatively short digestive tract, optimized for processing meat with ease [4]. Their stomach pH can range from 1 to 3 during digestion, regardless of the food type, demonstrating their adaptability [5].
The Myth: Different Digestive Rates and pH Levels
One of the main arguments against feeding kibble and raw food together is that they digest at different speeds. It's suggested that kibble, being carbohydrate-rich, digests faster than raw meat, which could lead to improper digestion and potential health issues. Furthermore, the theory proposes that carbohydrates in kibble can cause the stomach's pH to increase, making it less acidic. This altered pH, some "experts" suggest, could lead to fermentation, gas, diarrhea, and even allow harmful bacteria like E. coli and Salmonella to survive, potentially making your dog sick [2].
However, this theory does not hold up under scrutiny. Research indicates that the belief that kibble and raw digest at dangerously different rates is a myth. While meal composition does influence digestion speed, it's not in a way that necessarily causes harm [1]. A dog's digestive system does not make a distinction between "kibble" or "raw" once the food has been chewed, mixed, and reached the stomach [2]. The gastrointestinal (GI) tract simply processes macronutrients like water, protein, fatty acids, and carbohydrates, secreting acids, hormones, or alkaline substances based on their amounts [2]. Digestive enzymes can easily break down and gain essential nutrients from these macronutrients regardless of their source [2, 6].
Studies have even shown that kibble can dissolve faster than raw food, moving into the intestines more quickly, while raw food may take a bit longer to leave the stomach, but still within a healthy timeframe [3]. The assertion of gastric acid pH fluctuating significantly enough to warrant omitting fresh foods from a bowl of kibble (or vice versa) is factually incorrect [7]. Studies using telemetry technology show that gastric pH remains largely unaffected by traditional dog food (kibble), demonstrating that the dog's high acid output prevents a significant buffering effect by the food consumed [7].
The reality is that there isn't solid scientific evidence supporting the notion that mixing kibble and raw food will inevitably lead to these specific digestive problems due to altered pH levels or digestion rates. While any sudden diet change can upset a dog's stomach, the real focus should be on maintaining a healthy gut microbiome, not solely on the differences in how food is digested [2].
The Science Behind Digestion
Studies and practical experiences have shown that both kibble and raw food can be processed by a dog's digestive system efficiently [1, 3]. For instance, X-rays have demonstrated that kibble moves through the dog's gut at a similar speed to meat and bone [3]. This indicates that the digestive rates of these foods are not as different as some might believe [3].
Moreover, the tight pyloric sphincter in dogs prevents undigested lumps of meat and bone from passing into the intestines, ensuring that these components are adequately broken down before moving further along the digestive tract. This mechanism helps prevent potential issues related to mixing different types of food.
Current resources even suggest that by adding as little as 10-20% of raw meat or fresh food to your dog's kibble, you can not only diversify their diet and spark their interest but also enhance their gut health, leading to better overall health when done correctly [2]. Research indicates that raw food diets can promote a more diverse and abundant microbial composition in the canine gut compared to commercial kibble, leading to positive changes in healthy gut functions [8].
Food Safety First
Raw meat, as we all know, can carry bacteria such as Salmonella and E. coli, which can pose risks to both dogs and humans alike [9]. Therefore, it's crucial to handle and source raw meat properly to minimize contamination. Always practice good hygiene, wash your dog's bowls right after meals, and avoid leaving food out for extended periods. (For more information on raw dog food and salmonella, you can consult resources like The Balanced Canine article on the topic [10]). It's also worth noting that some studies have found Salmonella and other human pathogenic bacteria, including antibiotic-resistant strains, in dry pet foods and treats [8].
Practical Recommendations
While the science supports the idea that dogs can digest kibble and raw food together, there are some practical considerations to keep in mind:
Avoid Feeding Kibble with Meat on the Bone: It's generally advised not to feed kibble with meat on the bone. The dilution of stomach acids could potentially lead to improper digestion of the bone, which might be dangerous [5]. Instead, mix dry food with pre-made, ground raw foods available in most pet shops, but feed meaty bones separately.
Separate Meals: For those who prefer to feed both types of food, it's often recommended to do so in separate meals—raw in the morning and dry in the evening. This approach helps to avoid any potential digestive issues and ensures that each type of food is properly digested [1].
Gradual Introduction: If transitioning to a mixed diet, a gradual introduction is recommended. This allows the dog's digestive system to acclimatize to the new diet and reduces the risk of digestive upset [1, 2].
Nutritional Balance: While most kibble is designed to provide a complete and balanced diet, just like a properly prepared raw meal, it's essential to watch the overall balance when mixing the two and ensure it meets all their nutritional needs, remembering that these can look different from dog to dog. If this is done incorrectly, like with any diet, it can lead to an imbalance and issues further along the line.
Conclusion
The myth that dogs cannot digest kibble and raw food at the same time is largely unfounded. Dogs have highly acidic stomachs capable of efficiently processing a variety of foods, including a mix of kibble and raw [1, 3, 5]. While concerns about differing digestion rates and potential bacterial risks are valid, there's still a lack of extensive studies focusing specifically on mixing both kibble and raw meat. However, the research into raw and diverse diets and their impact on a dog's health is steadily increasing, and we must remember that scientific evidence should always supersede anecdotal myths [11].
By understanding the science and practicalities of canine digestion, pet owners can make informed decisions about their dogs' diets, ensuring they receive the best possible nutrition for their health and well-being.
Sources
[1] Oma's Pride. (n.d.). 11 Myths Versus Facts: Raw Food For Dogs & Cats. Retrieved from https://omaspride.com/blogs/articles/raw-feeding-myths-versus-facts
[2] We Feed Raw. (n.d.). Can You Combine Raw and Kibble in Your Pet's Diet?. Retrieved from https://wefeedraw.com/blog/can-you-mix-raw-food-with-kibble-yes
[3] Canine Care. (n.d.). Raw Feeding Myths: Can You Mix With Kibble and Raw?. Retrieved from https://canine.care/nutrition/raw-feeding-myths-can-you-mix-with-kibble-and-raw
[4] Wellness Pet Food. (2021, April 29). 16 Facts About Your Dog or Cat's Digestive System. Retrieved from https://www.wellnesspetfood.com/blog/16-facts-about-your-dog-or-cats-digestive-system/
[5] Dogs First. (n.d.). Switching to Raw Dog Food - Best Do It Slowly. Retrieved from https://dogsfirst.ie/switching-raw-dog-food/
[6] University of Guelph, OVC Pet Nutrition. (2022, November 17). Carbs & Dogs. Retrieved from https://ovcpetnutrition.uoguelph.ca/2022/11/17/carbs-dogs/
[7] Ra, H. (2021, January 10). Gastric pH in Dogs & how kibble versus a raw diet may affect digestion. Retrieved from https://www.hannahra.com/2021/01/gastric-ph-how-kibble-vs-raw-diet-may.html
[8] Big Dog Pet Foods. (n.d.). The Impact of Diet on the Canine Microbiome. Retrieved from https://www.bigdogpetfoods.com/guides/the-impact-of-diet-on-the-canine-microbiome
[9] Years.com. (n.d.). Raw Vs Fresh Dog Food. Retrieved from https://www.years.com/blogs/advice/fresh-vs-raw-dog-food
[10] The Balanced Canine. (n.d.). Debunking the Myth: Raw Dog Food and Salmonella Poisoning. Retrieved from https://www.thebalancedcanine.co.uk/articles/debunking-the-myth-raw-dog-food-and-salmonella-poisoning
[11] PupMed. (n.d.). 35892531. Retrieved from https://pubmed.ncbi.nlm.nih.gov/35892531/
